Audio

Here's a short track from a tape I made almost 20 years ago. The loudest call is a corncrake. The other strange ascending wittering sound is made by the Common Snipe (Gallinago gallinago). The sound is apparently generated by the tail feathers as the bird dives in its display flight. This dramatic display is described by Darwin in 'The Descent of Man' ¹ thus: 'This bird, during the pairing season, flies to "perhaps a thousand feet in height" and after zig-zagging about for a time descends to the earth in a curved line, with outspread tail and quivering pinions, and surprising velocity. The sound is emitted only during this rapid descent.' He goes on to explain that the outer tail feathers are 'peculiarly formed' and appear to be evolved specifically to create this sound. A similar sound is made by doves' wings, although in this case it appears to be merely incidental to the mechanism of normal flight rather than for the purpose of display.

This is from a 45 minute track I recorded one July afternoon in 1993 outside the village of Cros, Lewis, Outer Hebrides. It's the only survivor of my recordings from that era, as I used cassette tape at that time and the Hebridean damp subsequently got into my tapes.

1   Charles Darwin. The Descent of Man and Selection in Relation to Sex. 2nd Edition. London, John Murray, 1906.

Many thanks to Richard James, wildlife advisor at RSPB headquarters for help with identification.